1. Field of the Invention
The present invention relates to an ultrasound operation apparatus that performs an operation utilizing ultrasound vibrations and also suppresses cavitations that are generated accompanying ultrasound vibrations, as well as an ultrasound operation system and a cavitation suppression method.
2. Description of the Related Art
Ultrasound operation apparatuses that perform an operation on living tissue utilizing ultrasound vibrations produced by an ultrasound transducer have been widely used in recent years. When living tissue is caused to vibrate at an ultrasound frequency, in some cases cavitations are generated since the living tissue includes liquid. A cavitation indicates that when the pressure of a liquid becomes lower than a vapor pressure that is decided by the temperature of the liquid, the liquid evaporates and vapor bubbles are produced.
Accordingly, when compression waves are generated by ultrasound vibrations, cavitations are generated accompanying the generation of negative pressure.
Therefore, for example, Japanese Patent Application Laid-Open Publication No. 2002-537955 discloses an apparatus that irradiates ultrasound for medical treatment at a location inside the body, and monitors the level of cavitations at that time using a hydrophone.
Further, International Publication No. WO2005/094701 discloses an apparatus in which a sound pressure signal receiving probe is provided in a piezoelectric element for ultrasound irradiation, and which controls ultrasound irradiation conditions by means of sound pressure signals that are discharged from cavitation bubbles by the sound pressure signal reception probe.